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Print Size & DPI Calculator

How many pixels does an A4 flyer or a business card need? Pick the paper and the resolution and the answer appears, with the 3 mm bleed already added, so the check before you send artwork to the printer takes seconds. You can also work backwards from the pixels you already have.

Pick a paper and a resolution to get the pixel size

Common resolutions
2,894 × 4,093
Trim size (px)
2,977 × 4,176
With bleed (px)
210 × 297 mm
Finished size
47.4 MB
Uncompressed (CMYK)
Bleed Trim line Safe area for text
Artwork spec

    
    
  
    

  
    Everything is worked out inside this page; nothing you type leaves the browser. You can call it straight from a URL: /en/dpi/?paper=a4&dpi=350&bleed=3 / /en/dpi/?paper=meishi&dpi=350 / /en/dpi/?mmw=180&mmh=120&dpi=300
    
  
    

  

  

  

  
    
    
    How to Use
    
    
      
      
    1. Pick the paperChoose A4, a business card, a postcard and so on. For an odd size, choose “Custom size (mm)” and type the millimetres.
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    2. Set resolution and bleed300 dpi is the international standard and 350 dpi what Japanese printers ask for; bleed is normally 3 mm (1/8 inch in the US). Follow your printer's spec sheet when it says otherwise.
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    3. Take the pixel figure with youThe “with bleed” number is what goes into the new-document dialog. Copy the artwork spec to paste into a brief or an email to the printer.
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    About This Tool
    
    
    Dpi (dots per inch) is a density: how many dots fit into one inch, 25.4 mm. The pixels you need are mm ÷ 25.4 × dpi. An A4 (210 × 297 mm) at 350 dpi works out as 210 ÷ 25.4 × 350 = 2893.7, rounded up to 2894 px. Always round up — one pixel short leaves a hairline of white at the edge.
    
    
    Bleed is the margin you deliberately throw away so the guillotine has room to drift. Sheets are cut hundreds at a time and the blade lands within about a millimetre, so any colour or photo that reaches the edge of the page has to be extended 3 mm beyond the trim line. The “with bleed” figure is the canvas you actually create.
    
    
    
      
    350 dpi or 300 dpi?
    
      
    Printers in Japan usually ask for 350 dpi; almost everywhere else the standard is 300 dpi. The number comes from the halftone screen: at the common 175 lpi for colour work, twice the screen ruling is enough to build the dots, which lands at 350. In practice you will not see the difference, but if a spec sheet names a number, use it. Past 400 dpi a photograph gains nothing at all — the press cannot resolve it — while the file keeps growing. Line art, barcodes and single-colour type are the exception and do benefit from 600 dpi or more.
    
    
    
    
    
      
    Do not build a poster at 350 dpi
    
      
    A B1 poster at 350 dpi is around 10,000 × 14,000 px, over 500 MB flattened in CMYK. The further away a piece is read, the less resolution it needs. Posters and banners seen from a few metres are normally built at 150-200 dpi, and building wraps lower still (often at a tenth of final size, scaled up on the press). Large-format printers publish this in their spec sheets as “150 dpi at final size” or “350 dpi at 1:10” — follow whichever they give you.
    
    
    
    
    
      
    Keep text 3 mm inside the trim
    
      
    If bleed is the part that hangs outside, the safe area is the part you pull inside. When the cut drifts inwards, type sitting at the edge loses a sliver; even when it does not, text against the trim looks cramped. Three millimetres is the usual margin (two to three on something small like a business card, considerably more on the spine side of a saddle-stitched booklet). The dotted box in the preview is that area.
    
    
    
    
    
      
    Enlarging does not bring detail back
    
      
    When the effective dpi is short, typing 350 into Photoshop's Image Size dialog achieves nothing: it invents pixels by guessing from their neighbours. Detail does not return, and edges come out oddly hard. (Modern AI upscalers are far better, but hair, fabric and small type are still fiction.) Rescan or reshoot instead. For logos and type, ask for vector artwork — AI, PDF or SVG have no resolution at all and stay sharp at any size.
    
    
    
    
    
      
    Dpi, ppi, and the number stored in the file
    
      
    Strictly, ppi (pixels per inch) describes the image and dpi the dots the press lays down, but in production work the two are used interchangeably. The “350 dpi” recorded inside a JPEG or PSD is just a note: it changes no pixels. A file tagged 72 dpi prints perfectly well if it has the pixels. What matters is always the pair — pixel count and printed size — and their quotient is the effective dpi.
    
    
    
    
    
      
    File size, and what the working file will weigh
    
      
    The figure here is for a flattened, 8-bit, uncompressed file (pixels × channels). An A4 at 350 dpi with bleed is roughly 36 MB in RGB and 47 MB in CMYK. The working document, with layers, smart objects and effects, will be several times that, and a PSD tops out at 30,000 px per side and 2 GB (past which you need PSB). Looking at this number before you start saves rebuilding the file halfway through.
    
    
    
  
    

  
    
    
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